Method and apparatus for wrapping a stranded material about a core



Feb. 17, 1925. 1,526,572

W. B. TEN EYCK METHOD AND APPARATUS FOR WRAPPING A STRANDED MATERIAL ABOUT A CORE Filed Dec. 31, 1923 2 Sheets-Sheet 1 Feb. 17. 1925.

W. B. TEN EYCK METHOD AND APPARATUS FOR WRAPPING A STRANDED MATERIAL ABOUT A CORE Filed Dec. 31. 1923 2 Sheets-Sheet 2 Patented Feb. 17, 1925.

YUN'ITE'D STATES PATENT OFFICE.

B. EYOK, OF BLOOMFIELD, ELECTRIC COMPANY, INCORPORATED, OF

NEW YORK.

NEW JERSEY, ASSIGN OR TO WESTERN METHOD APPARATUS FOR WRAPPING A STRANDED MATERIAL ABOUT A CORE.

Application filed December a1, 1923. Serial No. 683,774.

To it may concern:

-Be it known that I WILLIAM B. TEN EYcK, a citizen-of the finited States, residing at Bloomfield, in the county of Essex,

State of New Jerse have invented certain new and useful Improvements in Methods and Apparatus for Wrapping a Stranded Material About a Core, of which the follow-,

ing is a'full, clear, concise, and exact des'cription. v

This inventionrelates to the method and apparatus for wrapping a stranded material around a core, and more particularly to a machine for applying ribbon or tape 'spirally to acontinuous core.

One manner of increasing the inductance of a conductor employed for the transmission of alternating current is to wrap the conductor spirally with a layer of wire or tape of magnetic material. This method is known in the art as continuous inductive loading as distjnguished'from lump loading by means of coils distributed along the conductor. Until recently iron has been considered to be the only: material available for continuous. loading. It has been discovered, however, that a more suitable material may be produced in the form of an alloy of nickel and iron. When these two metals are combined in the proper proportions and the alloy is given the proper heat treatment the resulting material has a very high permeability; at low magnetizing forces.

It has been found that when this alloy is subjected to stresses or strains, its permeability is materially lowered. In certain cases such deleterious strains and stresses occur during the heat treatment of the loading material and are 'due partly to the'con-" struction of the composite conductors and" also to the manner and method of wrapping the loading material thereon.

The'primary object of this invention is to wrap magnetic material about a conductor in such a manner that the magnetic material.

will not be subjected to any deleterious strains or stresses during its subsequent heat treatment.

A further object is to wrap the magnetic tape about a conductor in such a way that the tape will be positioned about the conductor in an evenand smooth closed spiral and with. a uniform spacing between the tape and the conducto In accordance with a feature of the invention, a serving device is provided which applies the tape evenly and with a definite pitch to form a practically closed spiral without any overlap.

In accordance with another feature of the invention, the tape is applied with a minimum degree of tension and is rolled upon the conductor in such a manner as to insure a definite spacing between the tape. and the conducto The invention will be more clearly under stood by reference to the accompanying drawing, in which Fig. 1 shows the mechanism employed in winding tape upon a conductor in accordance with this invention; Fig. 2 is an end view of the winding head of Fig. 1; Fig. 3 shows the method of applying tension to the tape; Fig. 4 is a sectional View of the serving device in its closed or operating position; Fig. 5 shows the serving device in its open position; Fig.6 shows the means by which the tape is applied to the conductor; and Fig. 7 is a view of a conductor wound in accordance with this invention.

Referring to the drawings, the winding head comprises a supporting plate 10, which 1s rigidly secured to a hollow spindle 11,

through which passes the conductor 12 to 1 which the tape is to be applied. This spindle is supported by means of suitable bearing brackets 13-13 and is rotated by means of the sprocket 14 and chain 15, the former being secured rigidly to the spindle by means of the key 16. The tape spool 17 upon which is wound the magnetic tape 18, is adapted to rotate freely about the spindle 19, secured to the plate 10 by means of the adjustable bracket 20. In order to prevent overthrow and to provide a certain degree of tensionto the tape, a device is emplo ed .consisting of a frictional band 21 'of leat er or similar material, which is adapted to engage with a hub portion 22 of the tape wheel 17. By means of the adjusting screw 23 threading into the member 24, it is an easy matter to vary the frictional resistance between members 21 and 22, and thus regulate the tension in the tape.

A serving device, the construction of which is shown in detail in Figs. 4 to 6, comprises a housing 25, the side walls of which support the pins 26, 26, upon which two parallel rollers 27, 27 are adapted to rotate. On one of the end walls is mounted a U- shaped bracket 28, which carries a grooved tape guiding wheel 29. This bracket is rotatable in its mounting so that it may be adjusted to give the desired angle of lay and at the same time maintain the tape in alignment with the tape spool. When the desired adjustment is obtained, the bracket is fixed in position by means of a set screw 30. A third roller 31, rotatable upon the pin 32, is'centrally located in the cover plate 33,

which is hinged to the housing 25 at 34/ This cover plate is provided at its free end with a pin 35, to which is secured one end of the helical spring 36. The other end of this spring is secured to pin 37, which is adjustably mounted at the midpoint of a U- shaped bracket 42 pivotally mounted to the housing 25 at 38. The position of pin 37 and therefore the tension of spring 36, is varied by turning adjusting nut 39, until the desired tension is obtained and the pin is then looked in position by the locking nut 40. A stop pin 41 is provided, as shown, to engage with a suitable slot in bracket 42 and thereby limit its motion. The device is secured to the winding head by means of the.

hollow spindle 43, which is threaded into the housing 25.

In the closed position, as shown by Fi s. 4 and 6, the roller 31 is forced against t e tape with a variable pressure, depending upon the tension of spring 36. The conductor, which is shown as a composite conductor, consisting of a central wire 45 surrounded by segmental strips 46, 46, is relatively stifl', and in passing over the reels, is subjected to bending forces which make it difficult to cause the conductor to pass in a straight line at the point of application of thetape. With a more flexible conductor it would be possible to maintain the conductor in close engagement with the rollers 27, 27 by ap lying the necessary tension to the tape, t us causing the conductor to move in a strai ht line at the point where the tape is applled, but with a relatively stiff conlow tension on the tape as is possible.

l uctor the strength of the tape is not sufficient to make such a procedure possible. Furthermore, it is desirable to maintain as Therefore, in an arrangement as shown, the tension on the tape is maintained at a value just high enough to permit the tape being drawn off the reel without danger of overthrow or kinking-and the tension on roller 31 is relied upon for the proper application of the tape.

In the operation-of this mechanism the conductor passes from a storage reel over a suitable guiding wheel 48 through the 1101- low spindles of the winding head and serving device, and then makes a complete turn about the driving capstan 49, after which 'the tape is drawn from the tape wheel 17 over guiding wheel 29 between rollers 27,

27 and secured to the conductor by means of solder or a wrapping of fine wire. With the end of the tape secured to the conductor, the mechanism is put in operation, causing the conductor to pass through the winding head at a predetermined speed, depending upon the speed of rotation of the winding head and serving device. The tape 18 is guided from the tape Wheel 17 to the serving device by means of the guiding wheel 29 and passes between the rollers 27, 27 and about the conductor. The roller 31 presses the tape against the conductor with a certain pressure, depending upon the tension of the spring 36, which may be varied to suit various conditions, such as the size of tape and its degree of hardness. The roller 31 also presses the conductor against rollers 27 27 thus to a considerable degree causing the conductor to pass in a straight line. The rollers, it will be noted, bear against the conductor at three practically equi-distant points, their contact with the conductor being in each case substantially a line contact. As the conductor moves in the direc- .latter exert a certain ironing action on the conductor, and thus overcome any danger of overlap. In case one turn of the tape starts to ride upon an adjacent turn, the ironing action of the rollers forces it over to make a butt joint and prevents any overla 74s previously stated, it is desirable to provide a certain amount of spacing between the conductor and the tape to prevent causing deleterious strains during the subse quent heat treatment. These stressesare especially present whenthe tape is wrap ed upon a composite conductor, and it iselieved that they are due to the fact that the segmental'strips 46, 46 upon being stranded about the central wire 45 do not present a cylindrical surface since the edges of the tape do not lie in close contact with the central wire but present spiral edges. During the cooling portion of the heat treatment the tape cools more rapidly at first than does the copper conductor due to its intimate contact with the cooling medium so that-the tape quickly comes into intimate tape spool carried thereby and a serving 4 points along its edges and the subsequent contraction of the copper therefore sets up. stresses in the alloy tape. A similaraction, although to a lesser degree, is present in the case of a solid conductor loaded with magnetic tape. In heating theloaded conductor, the copper member expands to a greater degree than does the alloy tape as a result of its higher coeflicient of expansion, and thus tends to eliminate any space normally existing between conductor and tape. Upon subsequent cooling, the tapecontracts more rapidly since it is 1n intimate contact with-the cooling medium, and it is thus drawn into close contact with the copper conductor and may be subjected to stresses, which will result in a decrease in permea-' bility of the loading material. It is therefore very important to insure'the necessary spacing between conductor and tape, which inthe present case isaccomplished by suitably adjusting the tension of spring 36, thus causing the pressure at which roller 31 is applied to the tape conductor to be the proper value, taking into consideration the elasticity of the-tape, to insure the desired which would decrease the After'receiving the coating 0 degree of spacing.

In order to maint-ain'the desired spacing in the completed conductor as illustrated in Fig. 7, the loaded conductor is treated with a coating of liquid bitumen which fills all interstices and by its cushioning efi'ect prevents the loading tape from stresses fpermeability.

liquid bitumen,'the conductor is provided with a thick coating 51 of insulatlng material such as a rubber com 'tion or gutta percha.

What is claimed is:

1. In a mechanism for serving tape spirally to a core, a rotatable winding head, a tape'spool carried thereb and a servin device rotatable with sai winding hea and'com'prising'a air of fixed rollers and a 'movable roller a apted to press the tape against the core with a definite pressure, and

means for varying said pressure.-

which the core is preed b 2. In a mechanism for serving tape spiral: 1y to a core, a rotatable winding head, a

device rotatable with said winding head and comprising a .pairof fixed rollers'against means of a third cylindrical roller, sai fixed rollers having parallel axes.

3. In a mechanism for serving tape spiral- 1y I to a core, a rotatable windinghead, a tape spool carried thereby and'a serving device rotatable with said winding head' and comprising a pair of fixed rollers for supporting the core at the point of applica-A .tion of the tape, a movable roller adapted to press the tape against thecore with a definite pressure, and means for adjusting said pressure. r

4. In a mechanism for servin tape spirally to a core, a rotatable win ing head, a tape spool carried thereby and a serving device rotatable with said winding head and comprising a pair of fixed rollers for supportmgthe core at the oint of application and comprising a plurality of rollers having their axes parallel to the direction of movement of the core and adapted to press the tape against the core with an adjustable predetermined pressure.

6. In a mechanism for serving tape spinallyto a core, a rotatable winding head, a tape spool carried thereby and a servin device rotatable with said winding hea and comprising a pair of fixed rollers, a guiding roller for guiding the tape between the fixed rollers and about the core with the desired angle of lay, and a movable roller adapted to ress the core with a pre etermined pressure.

7 In a mechanism for serving magnetic tape spirally to a conductor, a rotatable winding head, a tape spool carried thereby, and a serving device rotatable with said winding head to serve the magnetic tape upon the conductor with' a given angle of lay', said serving device comprising a plurality of rollers adapted to press the ta against the conductor with a ressure e-,

pendent upon the elasticity of t e tape and" adjustable means for varymg such pressure.

8. The method of serving a magnetic tape spirally about a conductor to provide a definite spacin between the tape and conductor which met od consists in guiding-the tape tape against the a tape from the supply spoolto the conductor I at the desired angle of lay and with a minimum tension in the tape and pressing the tape against the conductor across its width in such a manner as to give it the set necessary to provide the desired spacing.

In witness whereof, I hereunto subscri WILLIAM TEN EYCK.

be my name this 27th day of December, A. D. 

